Heat exchanger with improved flow

Abstract

A heat exchanger comprises a number of identical heat exchanger plates stacked in a stack. Every other heat exchanger plate is turned 180 degrees in its plane relative to its neighboring plates, and each heat exchanger plate comprises at least four port openings and a herringbone pattern comprising pressed ridges and grooves. The ridges and grooves are adapted to keep the plates on a distance from one another under formation of flow channels, wherein areas around the port openings are arranged on different levels, such that selective flow from the port openings to the flow channels is achieved. Dents are arranged in the ridges and grooves in the vicinity of any of the port openings, the dents being arranged to increase the flow resistance to promote a more even flow distribution in the flow channel.

The invention claimed is: 
     
       1. A heat exchanger comprising:
 (a) a number of identical heat exchanger plates stacked in a stack, wherein every other heat exchanger plate is turned 180 degrees in its plane relative to neighboring heat exchanger plates, and wherein each heat exchanger plate comprises at least four port openings and a herringbone pattern comprising pressed ridges and grooves; 
 (b) said ridges and grooves of the herringbone pattern providing contact points between neighboring heat exchanger plates and keeping the heat exchanger plates a distance from one another and providing flow channels, wherein said flow channels comprise a first flow channel and a second flow channel, wherein areas around the port openings are arranged on different levels, such that selective flow from the port openings to the flow channels is achieved; 
 (c) said port openings comprising a first inlet port opening open to said first flow channel and closed to said second flow channel, and a second inlet port opening closed to said first flow channel and open to said second flow channel; and 
 (d) wherein, seen from a frontal side of the heat exchanger plates, dents are arranged in the grooves of the herringbone pattern of the heat exchanger plates immediately adjacent said first inlet port opening, and dents are not arranged in the grooves of the herringbone pattern of the heat exchanger plates immediately adjacent said second inlet port opening, said dents in the grooves of the herringbone pattern being arranged to increase a flow resistance for fluid traveling in said first flow channel such that the fluid is directed toward a side of the heat exchanger plate where the second inlet port opening is placed to thereby promote a more even flow distribution in said flow channels, wherein said dents in the grooves of the herringbone pattern are placed such that said dents in the grooves of the herringbone pattern do not form contact points with the neighboring heat exchanger plates. 
 
     
     
       2. The heat exchanger of  claim 1 , wherein the dents are provided around two neighboring port openings, and wherein the dents in the areas of one of said neighboring port openings are placed in the ridges, and the dents in the areas of the other of the two neighboring port openings are placed in the grooves. 
     
     
       3. The heat exchanger of  claim 1 , wherein the heat exchanger plates in the stack are joined by brazing. 
     
     
       4. A heat exchanger comprising:
 (a) a number of identical heat exchanger plates stacked in a stack, wherein every other heat exchanger plate is turned 180 degrees in its plane relative to neighboring heat exchanger plates, and wherein each heat exchanger plate comprises at least four port openings and a herringbone pattern comprising pressed ridges and grooves; 
 (b) said ridges and grooves of the herringbone pattern providing contact points between neighboring heat exchanger plates and keeping the heat exchanger plates a distance from one another and providing flow channels, wherein the said flow channels comprise a first flow channel and a second flow channel, wherein areas around the port openings are arranged on different levels, such that selective flow from the port openings to the flow channels is achieved; 
 (c) said port openings comprising a first inlet port opening open to said first flow channel and closed to said second flow channel, and a second inlet port opening closed to said first flow channel and open to said second flow channel; and 
 (d) wherein, seen from a frontal side of the heat exchanger plates, dents are arranged in the ridges of the herringbone pattern of the heat exchanger plates immediately adjacent said second inlet port opening, and dents are not arranged in the ridges of the herringbone pattern of the heat exchanger plates immediately adjacent said first inlet port opening, said dents in the ridges of the herringbone pattern being arranged to decrease a flow resistance for fluid traveling in said second flow channels to thereby promote a more even flow distribution in said flow channels, wherein said dents in the ridges of the herringbone pattern in the heat exchanger plates are placed such that said dents in the ridges of the herringbone pattern do not form contact points with the neighboring heat exchanger plates.